In order to reconnect two hollow organ sections, e.g. two intestinal sections, at their open ends after a surgical intervention, i.e. for making an end-to-end anastomosis, different instruments and methods are used. End-to-end anastomoses can be made by suturing, by clip suture instruments, especially circular staplers, or by TFT (tissue fusion technology) instruments. Especially in the case of entero-anastomoses a circular stapler is used as a routine. In the case of anastomoses in the area of the large intestine the instrument is trans-anally inserted so that it is provided inside the intestine. After completed anastomosis the instrument is removed through the anus again. This procedure is not possible in the case of anastomoses of the small intestine as the path to the natural body opening is too long. The operation is made through the abdominal wall, wherein shortly ahead of the one end of the two intestinal sections to be connected a lateral incision is made through which the instrument is inserted so that it is provided inside the intestines again. After completed anastomosis by the clip suture instrument or the TFT instrument the latter is removed again. The lateral longitudinal incision at the one intestinal wall is manually sutured. A surgical system suited for this procedure is known from DE 10 2010 020 664 A1, for example.
A different method and instrument are known from WO 03/061487 A1 and DE 10 2008 048 293 A1. For making a vascular anastomosis in this case the end of a blood vessel is guided through a sleeve and is folded so that the tissue is located on the outside of the sleeve. The end of the second blood vessel is then pulled over the first blood vessel. The sleeve is provided with a first electrode array provided at the outer periphery of the sleeve. A ring having a second peripheral electrode array at its inner periphery is put over the two vascular sections pulled onto the sleeve. In this way the two vascular sections can be fusion-welded between the two electrode arrays at the outer ring and the sleeve upon applying HF current.
By axial overlapping of the vascular sections in the connecting area a tissue thickening and, respectively, a narrowing of the inner cross-section occurs in the area of the junction.